This invention relates to a process for the treatment of a liquid stream with two different reagents. The invention is particularly concerned with, but is not limited to, the deionisation of a stream of liquid employing deionising agents and particularly deionising resins.
It is known to deionise liquid by passing the latter first through a bed of anionic deionising resin and subsequently through a bed of cationic deionising resin; in theory in that way salts can be removed from the liquid. In practice, it is found that the treatment of the liquid in two such beds is not wholly effective and that, instead, it is necessary to pass the liquid subsequently and alternately in contact with the two types of resin. Thus, it has been proposed to pass the liquid through a column containing alternate layers of anionic and cationic resins. While such a column may be effective in removing salts from the liquid, it has the attendant problem of subsequently separating the resins for regeneration.